A Wireless Local Area Network (WLAN) is a wireless data network, a local area network is constructed in a wireless way, and data are sent and received in the air with electromagnetic waves but without cable mediums. The WLAN is a supplement and extension to the wired networking way, which makes computers in the network have a mobility, thereby solving the network connection problem of difficult implementation in the wired way rapidly and conveniently.
At present, devices such as a computer with a wireless network card and a mobile phone supporting Wireless Fidelity (Wi-Fi) serving as a client and so on can be collectively called mobile terminals, that is, the mobile terminals include terminal devices such as mobile phones supporting Wi-Fi and computers with wireless network cards, these mobile terminal all play a role of Station (STA) in the wireless local area network, and thus the mobile terminals are collectively called STAs below for an easy description.
As shown in FIG. 1, the WLAN includes STAs and Access Points (called APs for short), wherein each AP (such as an AP1, an AP2, . . . APn) notifies the STAs around the present AP by constantly sending Beacon messages, which enables the STAs to search out the present AP and then initiate an association request.
As shown in FIG. 2, a flow of establishing a connection between an STA and an AP in the related art includes:
the STA broadcasting a Probe request, and the AP that receives the request replying a Probe response to the STA, wherein connection authentication information required for accessing the AP is carried in the probe response; the STA sending an authentication request to the above AP, and the AP that receives the authentication request replying an authentication response to the STA; and the STA sending an association request to the above AP, and the AP that receives the association request replying an association response to the STA.
The connection is established after successfully performing probe, authentication and association between the STA and the AP, then the STA can access the local area network via the AP. It can be seen from the flow shown in FIG. 2 that, each STA must go through multiple interactions with the AP, and then the connection between the STA and the AP can be established.
In order to promote the number of accessing STAs and guarantee a network signal condition of each STA, multiple APs may exist in certain areas. When Beacon messages sent by the multiple APs are received, the STAs will decide which AP to access according to conditions such as the signal intensity of each Beacon message and so on; after one AP is selected, the connection between the STA and the AP is established through a flow shown in FIG. 2; and if the selected AP itself is overloaded currently, a connection request of the STA may be rejected, and this way can be called the simplest AP load balancing way. However, after one AP rejects the connection request of the STA, if another STA resends the connection request, it may still select to request the AP for a connection, and it is continually rejected by the AP, thus this causes that the STA cannot access normally.
There are various schemes with regard to the load balancing between multiple APs at present, for example, a method and system for implementing load balancing between access points, an AP and a wireless mobile terminal are disclosed in the invention with an application number of 200810112355.4. The method includes: an STA collecting APs which the STA can access currently and selecting one AP of the APs as a master AP; and when receiving Load-balancing Service Set (LSS) message sent by the STA, according to a load state of each AP in the LSS message to which the AP belongs, the AP making a selection in the APs which the STA can access and informing the STA to access the selected AP. In the method, a way for deciding the load is based on simple indicators such as the AP signal quality and so on. A method for wireless load balancing and an access controller are disclosed in the invention with an application number of 200810112188.3. Wherein, the method includes: an Access Controller (AC) receiving a request of accessing one AP sent by the STA, calculating a wireless load of the AP which the STA requests to access, judging whether the wireless load meets a preset acceptance condition, if yes, accepting the request of the STA; and if no, rejecting the request of the STA. In the invention, the number of accessing STAs within the wireless local area network and the traffic of each wireless interface are considered in the judgment on the load, and a method for load detection is further improved. However, in the above method, the judgment on the AP load is only based on indicators of the AP within the wireless local area network, such as the Wireless Fidelity (Wi-Fi) signal intensity, the number of accessing STAs and the traffic of each wireless interface within the wireless local area network.
As the 3rd-generation mobile telecommunications (3G) technologies such as the Wideband Code Division Multiple Access (WCDMA) and the Evolution-Data Only (EVDO), etc. and the Long Term Evolution (LTE) technology become more and more prevalent, wireless access point products (e.g., Eufi) accessing the Internet via the 3G/4G (the 4G is the 4th-generation mobile communication technology) gradually become important components of the wireless local area network.
It can be seen from the above descriptions that the current various AP load balancing schemes have apparent defects in solving the problem of load balancing between the special APs such as the Eufi.
1. The number of STAs accessing a certain AP is considered in all common AP load balancing schemes, but the STAs currently accessing the AP are not always in a busy state, that is, the AP which a large number of STAs access does not necessarily has the maximum load, thus the number of accessing STAs cannot accurately reflect an effective load of the particular AP.
2. The Eufi-type wireless access point products access networks of the mobile operators in a wireless way, but an essential difference exists between the wireless access way and the wired way, thus an exit bandwidth of the wireless access point and a networking way between the APs are all changed, and this cannot be solved by all the current various AP load balancing schemes.
3. Since an AP controller is used in all the common AP load balancing schemes, costs of the wireless network are increased; in some other schemes, a certain AP is used as the AP controller, but when a data interaction occurs between the AP serving as the controller and other APs, undesirable phenomena such as a transient data congestion within the wireless network will be caused, and the perceptibility of the user is stronger in the condition of busy wireless network, thus the user experience is limited.